What about price discovery is pointless? Would you prefer that prices update only once a day? Once a week? Once a month? Realtime pricing of securities and derivatives is critical for an efficiently functioning economy.
> if we imposed reasonable limits on the time required to hold an equity in order for a trade to be legally recognized
This would damage the ability of market makers to function, ultimately driving up the cost of offering pensions, 401k plans, retail investing, low fee ETFs, etc. If these companies are willing to spend their money competing for the ability to offer you a better, faster price, why is this upsetting?
If you're opposed to the emphasis on latency in equity markets, focus on rule 612 of Reg NMS, which prohibits showing more competitive prices.